Safrole-sulfoxide and sulfone insecticide and pyrethrin synergist



Patented Nov. 1, 1949 4 SAFROLE-SULFOXIDE AND SULFONE INSEC- TIClDE-AND PYRETHRIN SYNERGIST Martin E. Synerholm, Hastings on Hudson, N. Y., assignor to Boyce Thompson Institute for Plant Research, Inc., a corporation of New York No Drawing. Application November 9, 1946, Serial No. 708,921 I 2 Claims.

This invention relates to organic compounds o email-R and the sulfones by the formula o o wine-LR where R is a hydrocarbon radical derived from the mercaptan used in the addition with safrole or isosafrole consisting of aliphatic, aryl aliphatic, phenyl and p-chlorothiophenyl radicals. Particularly advantageous compounds are those where R. is an alkyl radical containing from 2 to 12 carbon atoms. The sulfoxides have but one oxygen attached to the sulfur, while the sulfones have two oxygens attached to the sulfur.

Representative compounds of the invention are those in which R is one of the following radicals: ethyl, isopropyl, n-butyl, isobutyl, n-amyl, n-hexyl, n-dodecyl, n-decyl, benzyl, o-chlorobenzyl, 2,4 dichlorobenzyl, 3,4 dichlorobenzyl, phenyl, p-chlorophenyl, B-ethoxyethyl, p-butoxyethyl, p-tZ-phenoxyethoxy) ethyl, and pbenzoxyethyl.

Examples of the effectiveness of these sulfoxides when tested against houseflies according to the standard Feet-Grady procedure (pp. 92-98 of Pyrethrum Flowers by C. B. Gradinger, 1936 edition) are shown in Table I.

From Table I, it is clear that the compounds described therein have marked insecticidal activity against houseflies. It is apparent, too, that, when used with a small amount of pyrethrins, the combined effect is greater than the effect would he were the activities of the compounds and pyrethrins simply additive; thus synergism is clearly demonstrated.

An aqueous emulsion containing acetone, 0.05% sodium lauryl sulfate, and 0.10% of the sulfoxide of the n-butyl mercaptan lsosafrole addition product was used against Aphis rumicz's, red spider, gladiolus thrips and Mexican bean beetles in Petri dish experiments. The leaves bearing the insects were sprayed with the emulsion and placed on wet filter paper in the dish. After standing open for one-half hour to a110,- the acetone to escape, the dishes were covered an left for 24 hours. The results of Table II indicate the kills obtained with the different-species of insect. It is clear from these results that the chemical tested is an effective insecticide. While Mexican bean beetles were not killed, the material acted as an effectiv repellent toward this insect.

In an experiment carried out to test the efiect of these compounds on growing plants, sprays containingup to 1.0% of the n-butyl-isosafrole addition product in a water suspension containing 10% acetone with 0.05% sodium lauryl sulfate were applied to the leaves of growing tomato, nasturtium and digitalis plants without noticeable injury even after several weeks contact.

These compounds are non-toxic to humans, non-injurious to plants in the concentrations used in insecticidal sprays, and are odorless. They are also stable toward atmospheric oxygen and, accordingly, possess distinct advantages over the thioethers from which they are derived. They are more effective than the thioethers as insecticides. The compounds are soluble in the usual organic solvents, such as those of petroleum origin, used for fly sprays.

The mercaptan addition products, formed from aliphatic or aryl aliphatic mercaptans and safrole or isosafrole, result, on oxidation, in sulfoxides. The mercaptan addition products formed from aryl mercaptans, such as phenyl mercaptans or p-chlorophenyl mercaptans and safrole or isosafrole, result, on oxidation, in sulfones. The oxidation is advantageously carried out with an excess of hydrogen peroxide, but may also be effected with nitric acid, permanganate, chromic acid, and electrolytic oxidation methods. In preparing the compounds of the invention, it was found convenient to dissolve the intermediate sulfide in acetic acid and to add an excess of 30% hydrogen peroxide to the acetic acid solution. After several hours the mixture is poured into water whereupon the sulfoxide separates as an oil or as a crystalline mass and is isolated by extraction with a suitable solvent (benzene or ether) which is later removed, or by filtration.

The solids have low melting points in the range 78 to .93", are pure white, odorless and soluble in kerosene and other related organic solvents used for insect sprays.

o I o Formula: c4 c4 o Cari 5.1.21.3

Type II-Obiainod by oxidation of the product lsoaai'mle and BBB.

Formula: 04 0 042 o (Jim-LR o dm-i-n Pymth- 00110., us Min, H 00m ound whereRis: r Knock- 24 on P 552.51. .1... K0 m For centPerceniPercent -c,m, 5511111.- 0.2 0.0125 04 a1 54 IIA----- 81g1.1s%1 rp yl 8-? 5 g; 5 3 a m 015 (it 125" 02 71 51 -0 b 1 1 81 1 M25 2; 1'13 1151,11- n Y 015 0.025 05 05 51 0.25 0.025 0s 22 50 02 0.0125 00 51 51 on 15511 m 3'2 0812 2 3 5 23 g IA 5 a, u

1 0.5 53 51 omu'nemy 0.5 0.025 98 02 55 0 11 1 8'? M25 28 2 5 m "Emu- W 015 0.025 100 9a 0.25 0.025 20 02 45 0.2 0.0125 51 11 44 0.2 0.0125 '10 a0 44 0.2 0.0125 88 54 0.2 0.0125 05 a1 50 0.2 0.0125 '10 20 44 0.2 0.0125 01 10 44 0.2 0.0125 02 2s 54 0.25 0.025 05 50 cm 11 1 1%5 8'32? g g g II-B any -C l1 0 G 5 m (film "2110 f2; 1 .1. .1. 1 :12 2% 5 11 2 IA 1 1 1- e a, p enoxye oxye y...

-o l-o-omoim 4101120 eth 0.25 0.025 02 05 50 W Y 0.2 0.0125 59 41 44 TABLE II Toxicity toward some agricultural insects of the aulfozide obtained by oxidation of the n-buiyi mercaptmz isosafrole addition product (icoia rim. at 0.1%)

Per Cent Per Cent Insect Host Kill Remark:

Km Check Namirtiumleavec.--. g? g Badapldei' Buahbeanleavea. g? g 4 Ants which were 1 iii In the Gladiolus 01111115.... Gladiolus florets (full) 59 4 flowers were also m V Moxicanbeaubeetlo. Buchbeanleaves I claim: and 1. An insecticidal composition comprising py rethrin and a compound of the group consist- 70 g o c n Of L O Y QV Q where R is a radical 25150050 from the group (6 05115121111: oi an alkyl radical containing from 2 to 12 carbon atoms, benzyl, o-chlorobenyl, 2,4- Number Name Date dichlorobenzyl, 3,4 dichlorobenzyl, phenyl, p-' 2,326,350 Gertler et a1 Aug. 10, 1943 chlorophenyl, p-ethoilyethyl, p-butoxyethyl, p-(2- 2,362,128 Gertler et al. Nov. '7, 1944 phenoxyethoxy) ethyl, and p-benzoxyethyl. 2,393,925 Morris et a1. Jan 29, 1946 2. An insecticidal composition according to 5 2,411,720 Gertler et al. Nov. 26, 1946 claim 1 in a liquid spray base of petroleum origin. 2,421,589 La Forge June 3, 1947 MARTIN E. SYNERHOIM. 2,421,570 La. Forge June 3,1947

OTHER REFERENCES REFERENCES CITED t tr u 10 Harvill e 9.1.: Con ibu one from Boyce z 21 :2; :gerences fi new: in Thompson Institute, vol. 13, No. 2, April-June p 1943, pages 8749. UNITED STATES PATENTS Number Name Date 7 2,297,024 Poms et 51 Sept. 29, 1942 15 

